The Quality Function Measure: reliability and discriminant validity of a new measure of quality of gross motor movement in ambulatory children with cerebral palsy

Abstract

GMPMGross Impaired gross motor development and function are defining features of cerebral palsy (CP). 1 Interventions aim to optimize what the child can do (functional skills) and how they do it (movement quality).2 Both are important prerequisites for advanced motor skills related to activity and participation. Enhancement of quality of movement may be an important precursor to attainment of new gross motor skills.2 While function is the ultimate goal, identifying challenges in quality of movement helps to guide therapists to develop individualized therapy approaches to enhance function. Without measuring movement, quality changes can only be inferred from improvements in other aspects of function, such as timed walk tests, acquisition of new motor skills, or indications of greater functional skill independence. Clinicians and researchers, therefore, remain uncertain about what aspects of quality are changing and when, how, and why. 'No difference' findings in trials that failed to assess quality of movement may have missed important changes in this underlying component of motor skill.Instrumented systems quantify selected attributes of movement quality (e.g. force, amplitude, speed), but their use is limited to specialized centres. Paediatric physiotherapists typically rate quality of performance through clinical observation and Gestalt perceptions of movement.3,4 The absence of appropriate clinical instruments to evaluate movement quality was the impetus to the development of the Gross Motor Performance Measure (GMPM), 3 created through an expert consensus approach as a companion to the original Gross Motor Function Measure (GMFM-88). 5The GMPM was designed to quantify key aspects of movement quality and evaluate change in children with CP and acquired brain injury. 6 Five attributes (Alignment, and it detected change with interventions (orthopaedic surgery, rhizotomy, and ankle orthoses). 11,12The GMPM remains the only published measure that addresses multiple components of quality of gross motor skills for children with CP. Other published upper or lower extremity/total body quality of movement scales are outlined in Table SI (online supporting information). Three concerns about the GMPM are its lack of item-specific response option descriptions, the need for highly experienced raters, 8 and the small representation of motor skills (20 GMFM-88 items). While the GMPM may be suitable for a therapist who is working with a child on basic motor skills that have quality components to them (e.g. Co-ordination and Dissociated movement are relevant attributes to assess for lying/rolling and crawling skills), its evaluation of movement quality across all aspects of motor function does not align well with goals of children who are working specifically on ambulation-based skills. For these children in Gross Motor Function Classification System (GMFCS) levels I to III, evaluation of movement quality should be intensely focused on standing and walking skills with a sufficient number of items to give a complete picture of...

Rater reliability and scoring duration of the Quality Function Measure in ambulant children with hyperkinetic movement disorders

“…These are all factors that may influence gross motor observational skills. Although it cannot be assumed that comparable reliability estimates will be achieved using raters with a different clinical background, our results are in line with those of Wright et al, 17 who utilized physiotherapist raters working across several centres. Nonetheless, it is recommended that reliability data be replicated with a broader range of raters recruited from multiple movement disorder centres, in conjunction with test-retest reliability estimates and subsequent evaluation of test responsiveness, to allow a more definitive conclusion to be made about the QFM as an evaluative measure for children with HMD.…”

“…Only a single validation study, involving children with predominantly spastic CP, is available for the QFM. 17 QFM scores differentiated children by Gross Motor Function Classification System (GMFCS) level, 19 providing evidence of discriminant validity. Excellent rater and testretest reliability were demonstrated for video-based rating, with coefficients ranging from 0.89 to 0.97.…”

Personalized approach to the treatment of supporting motor disturbances of the lower extremities in children with spastic forms of cerebral palsy

“…For patients at levels I, II, III/IV, and V on the GMFCS, this age is 5.0, 4.5, 3.5, and 3.0 years, respectively. After patients with CP attain these ages, the severity of neurological disorders does not change at later ages [14,15].…”

Comparison of a robotic-assisted gait training program with a program of functional gait training for children with cerebral palsy: design and methods of a two group randomized controlled cross-over trial

“…The primary outcome measures selected directly reflect those used in previous Lokomat studies (i.e., GMFM-66, 6MWT, Timed Up and Go and Canadian Occupational Performance Measure [COPM]) (Russell et al 2000; Russell et al 2013; Thompson et al 2008; Williams et al 2005; Law et al 1990), and expand into other ICF areas including movement quality (Quality FM, basic gait assessment of spatiotemporal variables via electronic walkway and observational assessment) (Wright et al 2008, 2014; Sorsdahl et al 2008), ROM and spasticity (Tardieu) (Scholtes et al 2006), advanced gross motor skills ( Challenge Assessment) (Wright et al 2012; Glazebrook and Wright 2014), functional abilities (i.e., PEDI Caregiver Assistance and ASK-30) (Haley et al 1992; Young et al 2000), and participation/QOL (i.e., step activity monitor, CAPE and KIDSCREEN) (King et al 2007; Ravens-Sieberer et al 2007; Bjornson et al 2014). Collectively, these outcome measures provide comprehensive information in areas of activity and participation in alignment with the WHO ICF framework (World Health Organization 2001).…”